DTI Predicts The Outcome Of RTMS-induced Movement Therapy In Acute Ickemic Stroke Patients

Purpose: To explore the potential imaging mechanism of repetitive transcranial magnetic stimulation(rTMS)for improving motor recovery in acute ischemic stroke patients with motor dysfunction through diffusion tensor imaging(DTI)technology.Method: Unilateral acute ischemic stroke inpatients from the Department of Neurology,Nanchong Central Hospital(Nanchong,Sichuan,China)were recruited from April to December 2015.The inclusive 15 patients were randomly assigned into a conventional therapy(CT)group(n= 8)and a rTMS + CT group(n= 7).Eleven age-and sex-matched control subjects were also enrolled.Besides the conventional therapy,the patients of the rTMS+ CT group also received rTMS treatment of 10 Hz,90% resting motor threshold(RMT)rTMS over the ipsilesional primary motor cortex(M1)for 10 days.The CT group only underwent conventional therapy.The rehabilitation assessments of Fugel-Meyer assessment(FM),National Institutes of Health Stroke Scale(NIHSS),Barthel index(BI),and DTI examination were performed before and after the intervention.The normal control group only underwent DTI examination.Results: No significant differences were found among these three groups,on general demography characteristic and pre-treatment score.First,compared with the normal patients,the FA significantly decreased in fifteen patients in the following regions: the ipsilesional posterior limb of internal capsule,bilateral anterior limb of internal capsule,bilateral forceps minor,bilateral corona radiate,the body of the corpus callosum,the left M1,and the right of medulla oblongata(t = 1.71,p <0.05,Uncorrected).Correlation analysis also indicated that in stroke patients,the FA value of the ipsilesional posterior limb of internal capsule,ipsilesional corona radiate,and the right of medulla oblongata were significantly positively correlated with FM scores(r= 0.70,p= 0.003;r= 0.72,p= 0.002;and r=0.61,p=0.010,respectively).Second,compared with the pre-treatment,the FA of the rTMS+CT group significantly increased in the ipsilesional M1,posterior limb of internal capsule,the contralesional supplementary motor area,corona radiate,posterior limb of internal capsule and medial frontal gyrus(t= 1.94,p<0.05,Uncorrected)after treatment.The increased FA values of the ipsilesional posterior limb of internal capsule and the body of the corpus callosum were significantly positively correlated with the enhanced FM scores(r= 0.780,p= 0.036;r= 0.810,p= 0.028,respectively).Third,the comparison of FA values between rTMS+CT group and CT group also revealed significant differences in the regions of bilateral M1,posterior limb of internal capsule and the left thalamus(t= 1.77,p<0.05,Uncorrected).Fourth,both the rTMS+CT group and CT group induced increased FM scores(rTMS+CT group:t= 6.73,p=0.001 and CT group:t= 9.72,p=0.000),BI scores(rTMS+CT group:t= 4.83,p= 0.003 and CT group:t= 5.92,p=0.001)and decreased NIHSS assessment(rTMS+CT group:t= 5.53,p=0.001 and CT group:t= 5.10,p= 0.001)after treatment.The FM of the rTMS+CT group and CT group after therapy showed a significant difference(rTMS+CT group:60.14±20.10 and CT group:38.25±21.11;t= 2.04,p= 0.041).Conclusion : the rTMS as a new choice may be more effective to restore brain microstructure and promote motor recovery for acute ischemic stroke patients with motor dysfunction.